1. Field of the Invention
The present invention relates to a direct current to direct current (DC-DC) converter and, more particularly, to a DC-DC converter using a power driving signal with fixed on-time.
2. Discussion of Related Art
In general, a DC-DC converter is used in various electronic apparatuses, such as cellular phones, radio-frequency (RF) communication apparatuses, etc., to convert an input supply voltage into an appropriate output voltage. The DC-DC converters are generally designed to restore an output voltage to a target level when an input supply voltage fluctuates.
The conventional DC-DC converters employ a method of restoring an output voltage using a ramp signal generated in the form of regular ripples. Thus, a ripple generator having a wide dynamic range is required in the conventional DC-DC converters to generate the ramp signal.
As a result, however, the conventional DC-DC converters requiring the ripple generator have a complicated circuit structure and require high current consumption. Also, the ramp signal generated by and used in the conventional DC-DC converters is vulnerable to noise.
Accordingly, there is a growing need to develop a DC-DC converter that does not include a ripple generator and thus has a simpler circuit structure, requires lower current consumption, and is more resistant to noises.